Device for guiding a thread

ABSTRACT

A device ( 3 ) for guiding a thread or the like is described, which includes a holding element ( 4 ), a thread roll ( 5 ) rotatably disposed on the holding element ( 4 ) to form a bearing gap ( 12 ), and a protective shield ( 14 ), which covers the bearing gap ( 12 ) at at least one axial end. According to the invention, the protective shield ( 34 ) is non-rotatably connected to the holding element ( 4 ).

FIELD OF THE INVENTION

The invention relates to a device for guiding a thread or similar,comprising a holding element intended for its assembly, a thread rollrotatably disposed on the holding element to form a circular cylindricalbearing gap and a protective shield, which covers the bearing gap at atleast one axial end of the thread roll and which has a passage with theholding element projecting through it.

BACKGROUND OF THE INVENTION

A known device of the type of interest here for guiding a threadincludes a holding element serving for mounting purposes and having theform of a shaft member, on the free end section of which a thread rollis rotatably disposed with sliding fit (e.g. DE 91 13 140 U1). To ensurean easy rotating capacity a central recess of the thread roll, which isconfigured as a cylindrical passage receiving the shaft member, musthave an inside diameter that is sufficiently larger than the outsidediameter of the likewise cylindrical shaft member, said diameteramounting to 1 mm to 2 mm, for example. As a result, in particular whenthe device is used in the textile industry and in knitting machines, forexample, dirt, lint and fluff particles, thread residues and othercontaminants can enter the bearing gap between the shaft member and thethread roll. As a consequence of this, the mounting for the thread rollbecomes increasingly stiffer with time during use, ultimately leading toits stoppage, so that the device must be cleaned frequently and evenreplaced. In spite of the advantage that in the known device the threadroll is fastened to the shaft member to be axially releasable by meansof a snap connection, additional work effort and undesirable machineoutages can occur as a result. Moreover, a disadvantage is that foulingof the bearing gap can cause varying thread tensions of the transportedthreads, and thus in the case of knitting machines can result indifferent stitch sizes or different quality of the produced knittedproduct, although an extreme smooth running ability of the thread rollsis required particularly with the guidance of elastic threads.

Similar problems arise when the thread roll is held to be axiallynon-displaceable in a known manner with a clamping ring fastenedcentrally on the holding element or is rotatably disposed on the holdingelement by means of a ball bearing (e.g. DE 926 805).

Therefore, a device of the aforementioned generic type is already known,in which the penetration of dirt particles or the like into the bearinggap is to be prevented by the thread roll being provided on its oneaxial end with a fully closed attachment and on its opposite end with aprotective shield in the form of a cover plate or the like covering thebearing gap and partially provided with sharp sealing edges. However, ithas not been possible hitherto to provide a satisfactory solution to thedescribed problem with such a device. Moreover, the protective shieldhinders simple dismantling, cleaning and/or replacement of the threadroll.

SUMMARY OF THE INVENTION

Starting from the above, it is an object of the invention to configurethe device of the aforementioned generic type such that the penetrationof dirt particles in the form of fluff, lint, dust and the like can besubstantially prevented.

A further object of the invention is to so configure the devicementioned above that the intervals between cleaning are increased.

Yet another object of the invention is to configure a device of the kindmentioned above for guiding a thread so that not only the penetration ofdirt particles or the like can be prevented and the cleaning intervalscan be increased but that also a favourable dismantling ability isenabled in the case of any necessary cleaning or replacement of thethread roll.

In addition to the above a further object of the invention is to designthe device mentioned above in such a manner that a looping or winding ofthreads or fibres around the holding element or adjoining parts will beprevented.

These and other objects of the invention are solved by means of aprotective shield which is non-rotatably connected to the holdingelement.

A significant reduction in fouling tendency of the device issurprisingly achieved with the non-rotatable arrangement of theprotective shield according to the invention. One reason for this couldbe that the comparatively high fouling tendency in the known devices iscaused not only by any dirt particles present being able to penetrateinto the open ends of the bearing gaps, but also fibres, thread residuesor the like being looped around the adjoining parts of the holdingelement through the rotating thread roll and therefore collecting onthis holding element and then gradually being increasingly drawn intothe open gaps. This effect is evidently prevented when using astationary non-rotatable protective shield, which counteracts thefouling tendency. In spite of this arrangement of the protective shieldaccording to the invention, however, the device can be configured sothat the thread roll can be easily removed from the holding element andattached onto this again.

Further advantageous features of the invention may be seen from thedependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention shall be explained in more detail below by way ofembodiments in association with the attached drawings:

FIG. 1 is a schematic perspective view of a device for guiding a threadaccording to the invention;

FIG. 2 shows an axial section through a first embodiment of the deviceaccording to the invention taken approximately along the line II-II inFIG. 1; and

FIGS. 3 to 5 are sectional views corresponding to FIG. 2 through threefurther embodiments of the device according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 schematically shows a thread guide 1, which guides a base thread(not shown) and an elastomer thread 2, for example. The base thread isguided in the usual manner, while the elastomer thread 2 is guided witha device according to the invention given the general reference 3. Thisdevice 3 includes a holding element 4 and a thread guide roll or inshort thread roll 5 rotatably disposed on an end section 4 a (FIG. 2) ofthe holding element 4. Another end section of the holding element 4 isarranged in a hole of a mounting 6 fastened to the thread guide I and isfixedly connected to the mounting 6 by means of a fastening screw. Onthe outer periphery, the thread roll 5 has, for example, a customaryV-shaped circumferential groove 5 a for the thread 2, wherein thecross-section of the circumferential groove 5 a decisive for the courseof the thread amounts to 11 mm, for example.

Devices 3 of this type are provided on circular knitting machines, forexample, as is generally known to the person skilled in the art, and donot therefore need to be explained in more detail (e.g. DE 91 13 140U1).

In the embodiment according to FIG. 2, in which identical parts areprovided with the same references as in FIG. 1, the thread roll 5 isconfigured in two parts. It includes a bearing section 8 a locatedradially on the inside and a thread guide section 8 b located radiallyon the outside, which is provided with the V-shaped circumferentialgroove 5 a, its outside shell face being expediently configured andarranged to be rotationally symmetric and coaxial to a rotational axis 9of the thread roll 5. The thread guide section 8 b is provided with arecessed seat 10, which extends over a large portion of its axial lengthas far as its one axial end and receives the bearing section 8 a. Thisseat 10 is radially widened at an opposite, open axial end, so that astep is formed, against which a flange 11 of the bearing section 8 aabuts during assembly and thus predetermines the relative axial positionof the two sections 8 a, 8 b in relation to one another. The outerperiphery of the bearing section 8 a and the inside shell of the threadguide section 8 b, which in the assembled state are both arrangedcoaxially to the rotational axis 9, are preferably connected to oneanother along an assembly gap formed between them by clamping action, byadhesion or other means for being axially fixed and non-rotatablerelative to each other and for forming a structural unit in one piece.

The bearing section 8 a additionally has a central, in this casecontinuous, recess having a cylindrical inside shell, into which recessthe end section 4 a of the holding element 4 provided with a cylindricaloutside shell can be inserted so that the bearing section 8 a isarranged on the end 4 a in the manner of a slide bearing and isrotatable around the rotational axis 9. As a result of this, inherently,a circular cylindrical bearing gap 12 is present between the insideshell of the bearing section 8 a and the outside shell of the endsection 4 a, said gap 12 having a specific width that can cause dirt,fluff or the like to penetrate and can thus lead to a reduction in theeasy rotating capacity or even to locking of the slide bearing.

According to the invention, the bearing gap 12 is covered with aprotective shield 14 on the side on which the holding element 4 ismounted on the circular knitting machine or the like. This shield 14 hasa central passage through which the holding element 4 projects, and isfixed to the holding element 4 by clamping, adhesion or other means in afixed, i.e. non-rotatable and sealed manner and so that dirt particlesor the like, coming axially from the right in FIG. 2, are held back bythe protective shield 14 and cannot reach the bearing gap 12. In theembodiment, the protective shield 14 consists of a thin plate, theexternal cross-section of which is preferably substantially larger thanthe diameter of the bearing gap 12 at the associated end of the bearingsection 8 a. As a result, it is also practically impossible for lint orthe like from radial directions to penetrate into an interstice locatedbetween the thread roll 5 and the protective shield 14, the width ofwhich needs only be so large that the thread roll 5 can rotate freelyand is not be braked by the fixed protective shield 14.

For axial fixture of the thread roll 5 on the end section 4 a, thelatter has a circumferential groove 16, which forms a catch groove,expediently lies in the vicinity of the face on the free end of the endsection 4 a and can receive a catch projection 17. The, for example,bead-shaped, catch projection 17 projects radially inwards from theinside shell of the recess passing through the bearing section 8 a andis configured so that it can either itself elastically deform or isprovided on an elastically deformable segment of the bearing section 8a, which can in turn deviate radially when the bearing section 8 a isplaced onto the holding element 4, with its passage having substantiallythe same cross-section as the end section 4 a.

For assembly of the described device 3 the thread guide section 8 a isfirstly slid onto the bearing section 8 a until it abuts against theflange 11 thereof, wherein the axial fixture of position and fixtureagainst rotation is achieved by clamping, adhesion or the like. Thestructure unit or thread roll 5 thus obtained is then—from the left inFIG. 2—placed onto the holding element 4 or its end section 4 a alreadyfixedly connected to the protective shield 14 until the catch projection17 locks in the circumferential groove 16 in the manner of a snapconnection. The thread roll 5 is now disposed on the end section 4 a tobe easily rotatable, but axially non-displaceable and protected fromfouling on the side of the protective shield 14. The created connectioncan be easily released again, where required, by axially pulling on thethread roll 5.

To also ensure protection against fouling on the opposite axial end ofthe thread roll 5, on an end remote from the protective shield 14, thethread roll 5, or its thread guide section 8 b in the embodiment, has afully closed cap-like attachment 18, which itself receives in particularthe free end of the end section 4 a and in the embodiment also thebearing section 8 a. The penetration of dirt or dust into the bearinggap 12 on the left side in FIG. 2 is impossible as a result of this.

The embodiment according to FIG. 3 differs from the embodiment accordingto FIG. 2 only by the position and the shape of a protective shield 20.Therefore, in FIG. 3 identical parts are provided with the samereferences as in FIG. 2. Here, the recess of the bearing section 8 a ofthe again two-part thread roll 5 with the end section 4 a passingthrough it has a widened portion 21 at the axial end remote from theattachment 18, the internal cross-section of said widened portion 21being substantially larger than the external cross-section of the endsection 4 a at this location. This widened portion 21 serves to receivethe protective shield 20 either completely or partially, as clearlyshown in FIG. 3. Moreover, on the side remote from the thread roll 5 theprotective shield 20 preferably has its smallest external cross-section,which gradually increases from there towards the thread roll 5 andexpediently increases conically. The sloping peripheral face of theprotective shield 20 thus formed expediently extends to close to theinside shell of the widened portion 21. As a result, the easy rotatingcapacity of the thread roll 5 is not impaired, while on the other handan open air gap 22, through which dust and dirt particles couldpenetrate, remains only in a region that is radially comparatively farfrom the rotational axis 9. Moreover, here the fixed protective shield20 also prevents threads or thread residues from being wound around theholding element 4 by the rotating thread roll 5 and being drawn into theactual bearing gap 12 in a region close to the rotational axis 9.

Otherwise, the device according to FIG. 3 corresponds to the deviceaccording to FIG. 2.

FIG. 4 shows a further embodiment of the device 3. A holding element 23is combined here with a protective shield 24 to form a structuralelement that can be produced in one piece. For this purpose, the holdingelement 23 has an end section 23 a being located axially at a front endand being provided with a cylindrical outer periphery, and a mountingsection 23 b located axially at a rear end, wherein the end section 23 ahas a substantially larger external cross-section than the mountingsection 23 b and/or the end section 4 a acting as axis in FIGS. 2 and 3.The end section 23 a has a cylindrical outside shell around which athread roll 5 can rotate that is a single part here. The thread roll 5has a recess 25, into which the end section 23 a can be insertedcoaxially and which is provided with a cylindrical inside shell, whichin the inserted state of the end section 23 a forms a circularcylindrical air gap 26 with the outside shell thereof, said air gap 26being dimensioned in accordance with a smooth-running slide mountingarrangement and substantially corresponding to air gap 22 of FIG. 3. Theend section 23 a and the thread roll 5 are rotationally symmetric andcoaxial to the rotational axis 9.

In the embodiment of FIG. 4 the protective shield 24 is formed by atransition section of the holding element 23 and arranged between theend section 23 a and the mounting section 23 b. This transition sectionhas an external cross-section that from the mounting section 23 bgradually becomes larger towards the end section 23 a and preferablyincreases conically. As a result, in the same manner as the practicalexample of FIG. 3, the air gap 26 is located at a comparatively largeradial distance from the rotational axis 9 and the protective shield 24forms a sloping, stationary ramp, which counteracts the winding ofthread residues or the like and protects the air gap 26 fromcontaminants.

The end section 23 a according to FIG. 4 is preferably hollowcylindrical and is thus provided with a seat 27, into which an insert 28projects at least partially. The insert 29 is also hollow cylindricaland has a shaft member 29 at least partially passing through it. Member29 at an end of the end section 23 a remote from the mounting section 23b also passes through a cap-like attachment 30 of the single-part threadroll 5 that corresponds to the attachment 18 according to FIG. 3. In theassembled state according to FIG. 4, the bearing section 23 a, theinsert 28, the shaft member 29 and preferably also the attachment 30 arearranged coaxially to one another and to the rotational axis 9. In thiscase, the shaft member 29 is preferably fixedly connected to theattachment 30 to form a seal and rotatably disposed in the insert 28,which in this case is fixedly connected to the bearing section 23 a byclamping, adhesion or the like. On account of this configuration, abearing gap 12 a to be protected is formed between the insert 28 and theshaft member 29, said gap 12 a corresponding to bearing gap 12 in FIGS.2 and 3. For releasable assembly of the thread roll 5 it is proposed,similar to FIGS. 2 and 3, to provide the shaft member 29 with an outercircumferential groove 31, which forms a snap connection with a radiallyinward pointing catch projection 32 provided on the insert 28. As aresult, the prefabricated structural unit consisting of the thread roll5 and shaft member 29 can be inserted axially—from the left in FIG.4—into the likewise prefabricated structural unit consisting of theholding element 23 and the insert 28 or be released from this again, ifnecessary.

Otherwise, the embodiment according to FIG. 4 corresponds to theembodiments according to FIGS. 2 and 3, and therefore the samereferences have been used for identical parts.

A embodiment of the invention currently considered the best is shown inFIG. 5. In the same manner as FIG. 4, the thread roll 5 is configured ina single part. It has a recess 33 coaxial to the rotational axis 9,which at one end has a radial widened portion 33 a forming a radialshoulder and receiving a protective shield 34. The internalcross-section of the widened portion 33 a is significantly larger thanthe external cross-section of the holding element 4 that is configuredthe same as in FIGS. 2 and 3. On a side facing the thread roll 5, theprotective shield 34 has an axial projection with a steppedcross-section and containing a central section 34 a and an assemblysection 34 b at the end. Both the protective shield 34 and theprojection 34 a, 34 b have a passage running through them, with whichthe protective shield 34 is slid onto the holding element 4. Moreover,the protective shield 34 can be connected to the holding element 4 byclamping in an axially non-displaceable and non-rotatable but alsoreleasable manner. For this purpose, like in FIGS. 2 to 4, the endsection 4 a of the holding element 4 has the circumferential groove 16,into which a resiliently configured or resiliently disposed catchprojection 35 provided on the assembly section 34 b of the protectiveshield 34 can engage when the protective shield 34 is slid axially ontothe holding element 4. In this case, the end section 4 a and theassembly section 34 b preferably have substantially the same, butnon-circular external or internal cross-sections so that afterengagement of the catch projection 35 in the circumferential groove 16the protective shield 34 is not only connected to the holding element 4in an axially fixed manner, but also in a non-rotatable manner. The snapconnection thus formed can also be released again, where necessary, bypulling axially on the protective shield 34 or the thread roll 5.

In contrast to FIGS. 2 to 4, the thread roll 5 in the embodimentaccording to FIG. 5 is not disposed to be easily rotatable on theholding element 4 by means of a slide bearing, but by means of a ball orroller bearing 36. For this purpose, e.g. an inner race of the bearing36 is fastened on the assembly section 34 b of the protective shield 34,for example, by a sufficiently firm clamping fit, whereas the outer raceof the bearing 36 is fastened fixedly to the inner periphery of therecess 33 of the thread roll 5. The thread roll 5 is therefore rotatablydisposed on the holding element 4 indirectly, and not directly, via theassembly section 34 b.

As FIG. 5 shows, the external cross-section of the assembly section 34 bis smaller than the internal cross-section of the recess 33 to asufficient degree to allow sufficient space for the bearing 36. Incontrast, the external cross-section of the central section 34 a is onlyslightly smaller than the internal cross-section of the recess 33, sothat in the assembled state of the device a narrow air gap 37 is formedthat allows smooth-running rotation of the thread roll 5 relative to theprotective shield 34 and that substantially corresponds to the air gaps22 and 26 in FIGS. 3 and 4. To the outside the air gap 37 and thebearing 36 are protected from contaminants by a plate-shaped section 34c of the protective shield 34 that covers them radially and comes to liein the widened portion 33 a. In addition, a narrow air gap 38 isexpediently provided between the inside of the section 34 c and an endface of the thread roll 5 facing it, so that the free rotating capacityof the thread roll 5 is not hindered at this location by the protectiveshield 34. A defined width of the air gap 38 can be achieved, forexample, by fixing the axial position of the bearing 36 by means of astep 39 on the inner periphery of the thread roll 5 and also by means ofa step 40 between the two sections 34 a, 34 b of the projection 34.Surprisingly it was discovered that a somewhat broader air gap 37 leadsto a longer lifetime as compared with a too small air gap 37 in thisembodiment. This possibly is a result of the fact that dirt, fluff orthe like that has entered the air gap 37 does not lead to a remarkablediminuation of the free rotatability of the tread roll 5.

As a result of the stationary protective shield 34 and the stepped formof its projection 34 a, 34 b, an excellent seal is obtained on an axialend of the bearing 36. At the opposite end the possibility of fouling bydust, lint or the like is excluded, as in the other embodiments, by theattachment 30 of the thread roll 5.

If it is intended to release the thread roll 5 from the holding element4, the entire structural unit consisting of the thread roll 5,protective shield 34 and bearing 36 can be pulled off axially to theleft in FIG. 5 releasing the snap connection (parts 16, 25). Theclamping connection between the protective shield 34 and the inner raceof the bearing 36 can then be released, if required.

The thread roll 5 or its parts 8 a and 8 b as well as the insert 28 arepreferably made of plastic injection mouldings and it is particularlyadvantageous if they are made from plastics with good sliding propertiesand, like the protective shields 14, 20, 24 and 34, are made from amaterial with antistatic effect.

The invention is not restricted to the described embodiments, which canbe modified in a variety of ways. It is possible, for example, toarrange the circumferential or catch groove 16, 31 in the inside shellof the respective passage of the bearing section 8 a, the insert 28 orthe assembly section 34 b and arrange the catch projection 17, 32 or 35on the outside shell of the end section 4 a or the shaft member 29, orto provide these parts in any other expedient manner. In this case, theaxial positions of the catch projections and the catch grooves can beselected as may be seen from FIGS. 2 to 5. In addition, it could beprovided that a respective catch projection 17, 32 or 35 and acorresponding catch groove 16, 31 are arranged at both axial ends of thethread roll 5 in order to thus even further restrict fouling in thebearing gap 12 and 12 a as well as in the region of the bearing 36. Inaddition, it should be understood that the device 3 according to theinvention can also be applied to machines other than circular knittingmachines and for guidance of thread other than textile threads, inparticular also thin strips or wires, glass fibres or the like.Moreover, a similar assembly would also be possible with differentlyconfigured thread guide rolls, in which case in particular a differentcolouration, e.g. a black and white colouration, of the thread roll 5 isexpedient to thus render any stoppage of a thread roll directlyrecognisable even from far away. The structure of the protective shields14, 20, 24 and 34 can also be different from the illustrations in FIGS.2 to 5, in particular with respect to the relative size dimensions andcross-sectional forms, wherein in particular the protective shields 20and 34 need only project axially into corresponding recesses of thethread roll 5 or its bearing sections 8 a. Finally, it should beunderstood that the different features can also be applied in differentcombinations from those described and represented.

It will be understood, that each of the elements described above or twoor more together, may also find a useful application in other types ofconstruction differing from the types described above.

While the invention has been illustrated and described as embodied in adevice for guiding the thread of a circular knitting machine, it is notintended to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the forgoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

1. Device for guiding a thread (2) or the like, comprising a holdingelement (4, 23), a thread roll (5) rotatably disposed on the holdingelement (4, 23) to form a circular cylindrical bearing gap (12, 12 a)and a protective shield (14, 20, 24, 34) covering said bearing gap (12,12 a) at at least one axial end of said thread roll (5), having apassage through which said holding element (4, 23) projects and beingnon-rotatably connected to said holding element (4, 23).
 2. Deviceaccording to claim 1, wherein said protective shield (14, 20) consistsof a plate arranged at an axial distance from said thread roll (5). 3.Device according to claim 1, wherein said protective shield (14, 20, 34)has a maximum external cross-section which is larger than across-section of said bearing gap (12, 12 a) at an axial end facing saidprotective shield (14, 20, 34).
 4. Device according to claim 1, whereinsaid protective shield (20, 34) lies at least partially in a recess (21,10 a) of said thread roll (5).
 5. Device according to claim 4, wherein aside remote from said thread roll (5) said protective shield (14, 24)has a smallest external cross-section, which gradually increases fromthere towards said thread roll (5).
 6. Device according to claim 5,wherein said protective shield (14, 24) has a conical outer periphery.7. Device according to claim 4, wherein said protective shield (34) hasan axial projection (34 a, 34 b) which projects at least partially in arecess (33) of said thread roll (5) and on which is fastened an innerrace of a ball or roller bearing (36) for the rotatably mounting saidthread roll (5).
 8. Device according to claim 7, wherein a centralsection (34 a) of said projection forms an air gap (37) and wherein atan axial end remote from said ball or roller bearing (36) saidprotective shield (34) has a section (34 c) with an externalcross-section, which is larger than a cross-section of said air gap(37).
 9. Device according to claim 7, wherein said projection (34 a, 34b) is connected to said holding element (4) by means of a snapconnection (16, 36) in a releasable but substantially non-displaceablemanner in axial direction.
 10. Device according to claim 1, wherein saidthread roll (5) is configured in two parts and has a bearing section (8a) being located radially on an inside and having a recess for saidholding element (4) and a thread guide section (8 b) being locatedradially on an outside and being projected by said bearing section (8a).
 11. Device according to claim 10, wherein said thread guide section(18 b) is provided with a V-shaped circumferential groove (5 a). 12.Device according to claim 10, wherein said bearing section (8 a) andsaid thread guide section (8 b) are fixedly connected to one another.13. Device according to claim 10, wherein at an end remote from saidprotective shield (14, 20, 24, 34) said thread roll (5) has a fullyclosed cap-like attachment (18, 30).
 14. Device according to claim 13,wherein said attachment (18) is provided on said thread guide section (8b).
 15. Device according to one of claims 10, wherein said bearingsection (8 a) is connected to the holding element (4) in a mannerreleasable but substantially non-displaceable in axial direction bymeans of a snap connection (16, 17).
 16. Device according to claim 1,wherein said holding element (23) has an end section (23 a) beinglocated axially at a front portion, being intended for arrangement in arecess (25) of said thread roll (5) and being provided with acylindrical outer periphery, and a mounting section (23 b) being locatedaxially at a rear portion, being intended for assembly and having asmaller external cross-section than said end section (23 a), and thatsaid protective shield (24) is formed from a transition section having awidening external cross-section and being arranged between said mountingsection (23 b) and said end section (23 a).
 17. Device according toclaim 16, wherein said transition section has an external cross-section,which widens conically from said mounting section (23 b) towards saidend section (23 a).
 18. Device according to claim 16, wherein said endsection (23 a) is hollow cylindrical.
 19. Device according to claim 18,wherein arranged in said end section (23 a) is a hollow cylindricalinsert (28), which receives a shaft member (29), which is coaxial tosaid mounting section (23 b) and projects partially out of said insert(28) and at an end of said end section (23 a) remote from said mountingsection (23 b) has a section, which projects out of said insert (28) andprojects through said attachment (30) provided on said thread roll (5).20. Device according to claim 19, wherein said shaft member (29) isfixedly connected to said attachment (30) to form a seal and isrotatably disposed in said insert (28).
 21. Device according to claim19, wherein said insert (28) is fixedly connected to said end section(23 a) and is connected to said shaft member (29) in a releasable mannerbut in an axially substantially non-displaceable manner by means of asnap connection (31, 32).
 22. Device according to claim 1, wherein saidthread roll (5) or its parts (8 a and 8 b), said protective shields (14,20, 24, 34) and also said insert (28) are made from a sliding materialwith antistatic effect.